As the battleground state of Florida looked increasingly certain to go to President Donald Trump, Democratic party voters in the overwhelmingly blue capital Washington put on brave faces and said they were preparing to dig in for a long haul.

"We wanted to come out to support Joe Biden and Kamala Harris, hoping for a celebration," said Tammi Girgenti, a 51-year-old retired government official, adding: "I'm a little disappointed with Florida, that's my home state."  

"I'm feeling okay, a little bit nervous and a little apprehensive, but I think Biden can squeeze it out by the end of the night or tomorrow or the next day," she laughed.

Trump was also leading in several other key battleground states including Pennsylvania.

Jake, a 22-year-old undergraduate student who came with a group of friends, summed up their mood: "We're not feeling too good, but I know that the mail-in the early voting was always going to be kind of later, and so I went in tonight bracing for an early Trump lead, but I think that Biden can still pull it off."

Starting from the afternoon, crowds had converged on two streets recently named Black Lives Matter (BLM) Plaza by the mayor of Washington, which was the focal point of opposition to Trump during racial justice protests over summer. 

Others filled a nearby park, McPherson Square, after the traditional area for such gatherings, Lafayette Square, was shut off by a perimeter fence that went up some weeks ago. 

A new, unscalable barricade has also gone up inside the perimeter, and dozens of police watched on.

There were no signs of tension between the police and the crowd, who were almost all anti-Trump. Supporters of the president were a rare sight, but when one appeared and expressed their views, they were quickly swarmed by Biden followers who wanted to debate them.

A brief scuffle broke out at one point, though it was unclear who it was between. The fight broke up when a smoke bomb was thrown -- apparently not by police, who had already left the area.

'Feel the energy'

Some had traveled from far and wide to be in Washington for the historic occasion.

Ruby Estoy, 40, and her friend Concetta Leanza, 34, together with Leanza's terrier Hercules came from Florida on Sunday.

"We came here just to feel the energy and to be here, and to really make sure that our voices get heard," said Estoy.

The pair, who both work in the financial sector, said they voted early for Biden.

"Vote him out!" stressed Estoy.

Another pair of friends, Susan Ryan and Lauren Sanders, both writers from New York, said that while they were hoping to celebrate, "we also are not going to leave the streets, until we know that Donald Trump is going to agree to go peacefully," said Sanders, 55.

First time voter Greta Jones, from Maryland, was bopping along to a go-go band set up in a truck on the street.

"I'm here to show a united front, I voted for Biden and Harris," said 20-year-old grocery store worker.

Asked how she was feeling about the final result, Jones said: "Honestly I'm scared because either way it's going to be a civil war, and I'm not mentally prepared for that."